This invention relates to record disk drives. More specifically, this invention relates to a disk drive device which engages a reference surface in a disk cartridge and aligns the disk contained therein with the drive's transducer and motor spindle when the cartridge is inserted into the drive.
It is well known that the spatial alignment of a disk with the transducer used to store and retrieve data to and from that disk is of critical importance. When a disk is made a permanent part of the disk drive there is relatively little problem in precisely obtaining this alignment. However, when such a disk is made portable relative to the drive, various problems are encountered in balancing the need for a portable, non-integral disk with the importance of a proper disk to transducer alignment when the drive is in operation. One solution has been to have the transducer and/or motor held in a noninterfering position while the disk is being inserted into the drive. After the disk cartridge is properly inserted, the transducer and/or motor is returned to its operating position. See for example U.S. Pat. Nos. 4,502,083--Bauck et al.; 3,772,665 --Hertrich. The problem is amplified when attempting to access two read/write surfaces simultaneously, and the corresponding solutions have been more complex and susceptible to imprecision. See for example U.S. Pat. Nos. 3,990,111--Elliot; 4,001,888--Morgan; 4,151,573--Tandon et al.; 4,414,591--Wenner; and 4,423,449--Hasegawa.
In all of the above cited references, the degrees of freedom of movement between the disk surface and the transducer surface are greater than that required for the read/write (i.e., retrieve/store) function itself. For example, in typical prior art the transducer has a component of movement in a normal direction relative to the disk; however, movement in a radial direction relative to the disk is all that is required for the read/write operation. This extra degree of freedom introduces greater possibilities of imprecision in aligning the disk with the transducer and/or motor spindle.